1. Field of the Invention
The present invention relates to a diagnostic method and apparatus using light. More particularly, the present invention relates to a method and apparatus for measuring blood hemoglobin concentration, oxygen saturation, pulse rate, respiration rate, and degree of aging of blood vessels using light.
2. Description of the Related Art
Hemoglobin in red blood cells is responsible for supplying oxygen throughout the human body and is essential for the normal function of every cell in the body. A reduced supply of oxygen to the body restricts the intercellular energy metabolism in tissues, and a lack of oxygen for a prolonged period of time results in death. Hemoglobin content is used as a measure of anemia and is measured to qualify a blood donor and to determine the volume of blood that may safely be taken from a blood donor.
There is a need for real-time monitoring of a patient's condition by measuring hemoglobin concentration, oxygen saturation, pulse rate, respiration rate, and degree of aging of blood vessels, especially in patients that are bleeding as the result of a traffic accident and in patients in need of a surgical operation. In addition, there is a need for introducing a convenient method that enables a health care provider to check frequently biological conditions of children and pregnant females, in particular, by measuring these parameters.
Conventionally, hemoglobin concentration is measured in a medical institute for therapeutic or prophylactic purposes through chemical analysis of blood drawn from the body. The measurements of pulse rate, respiration rate, or degree of aging of blood vessels are typically conducted only by health care providers. Therefore, a convenient method enabling the general public to personally measure each of these parameters at home is required.